Detection of Serpula lacrymans infestation with a polypyrrole sensor array

The use of a conducting polymer sensor array based on polypyrrole for the detection of Serpula lacrymans infestation is described. Ten gas sensitive polypyrrole films each with different counter-ion, which are electrochemically deposited on gold-plated copper substrates by a novel brush plating method, form the array. The array was exposed to headspace vapours of infected and non-infected wood, and resistance measurements were taken at 10 s intervals, enabling calculation of the sensory response. The peak percentage divergence from baseline during each 60 s exposure for each sensor was calculated, and this data treated using two pattern recognition techniques to assess the array's ability to differentiate infected and non-infected wood. Principal components analysis broadly grouped the samples although there was some overlap in the data. Linear discriminant analysis was much more successful, classifying the samples with 0% error.